fix: fix runtime error for libcamera0.7 (#205)

* fix: fix runtime error when overwriting Request::controls()
* fix: fix MergePolicy of merge operation

Signed-off-by: Patrick Gehrsitz <mryel00.github@gmail.com>

Author: mryel00

device/libcamera/buffer.cc

@@ -80,7 +80,10 @@ int libcamera_buffer_enqueue(buffer_t *buf, const char *who)
   auto const &camera = buf->buf_list->dev->libcamera->camera;
 
   request->reuse(libcamera::Request::ReuseBuffers);
-  request->controls() = std::move(buf->buf_list->dev->libcamera->controls);
+  request->controls().merge(
+    buf->buf_list->dev->libcamera->controls,
+    libcamera::ControlList::MergePolicy::OverwriteExisting
+  );
 
   if (camera->queueRequest(buf->libcamera->request.get()) < 0) {
     LOG_ERROR(buf, "Can't queue buffer.");